“There are two sorts of wealth-getting. The most hated sort, and with the greatest reason, is usury.”

— Aristotle, Politics, 350 BC

For centuries, writers and artists preoccupied themselves not with the economics of lending and borrowing, but with its moral dimensions.2 Usury—or lending on interest—was condemned by nearly every ancient authority from Plato onward. Medieval theologians followed their lead, placing avarice at the head of the list of seven deadly sins, and identifying usury as its greatest expression.3

In practice, however, lending and borrowing proceeded briskly and at all levels of the pre-industrial economy, if not in forms that we would recognize today.